Eduardo Sanchez has been fantastic for the Cardinals, quickly ascending to a prominent bullpen role by throwing 29 innings with a 1.88 ERA and 33 strikeouts, but now the 22-year-old’s rookie campaign is on hold thanks to a shoulder injury.

Sanchez left the team and traveled back to St. Louis for an MRI exam yesterday that revealed no structural damage, but the Cardinals placed him on the disabled list anyway and general manager John Mozeliak told Joe Strauss of the St. Louis Post Dispatch that returning in 15 days is no sure thing.

Strauss writes that Mitchell Boggs, who just a couple weeks ago was demoted to the minors for the stated purpose of getting work as a starter, will be elevated into a higher-leverage bullpen role in Sanchez’s absence.